This invention generally relates to ceramic particles that are useful in applications where high strength and low specific gravity are desirable. More specifically, this invention is concerned with ceramic proppants that may be used to increase the efficiency of wells used to remove fluids from geological formations.
The chemical and physical characteristics of proppants have been disclosed in numerous patents and patent applications including: U.S. Pat. No. 4,632,876; U.S. Pat. No. 7,067,445; US 2006/0177661; US 2008/0223574 and US 2011/0265995. Proppants may generally be classified as made from naturally occurring materials, such as sand, or manufactured materials that have been made by blending solids and liquids to form a mixture which is then formed into a plurality of small spherical particles. The particles are then heated to form sintered ceramic particles.